Texas Instruments UCC27321DGN

Overview

UCC27321DGN from Texas Instruments is a single-channel, non-inverting, 9-A peak-current low-side MOSFET driver in thermally enhanced MSOP-PowerPAD™ (8-pin) package. It delivers ±9 A peak drive current at the Miller plateau region, supports 4.5–15 V supply voltage, features TTL/CMOS-compatible inputs independent of VDD, and includes an active-high enable pin (ENBL) with 100-kΩ internal pull-up. It is used to drive N-channel power MOSFETs in high-frequency switch-mode power supplies.

For engineers reviewing the UCC27321DGN datasheet, UCC27321DGN pinout, UCC27321DGN application, or UCC27321DGN equivalent, key selection criteria include its 20-ns typical rise/fall time with 10-nF load, 25-ns/35-ns propagation delay (rising/falling edge), ±9-A Miller-region drive capability, thermal resistance of 4.7°C/W (θ_jc), and industry-standard 8-pin SOIC-compatible pinout extended with ENBL on pin 3.

Technical Context

The UCC27321DGN implements a hybrid TrueDrive output stage combining bipolar and MOSFET transistors to deliver efficient constant-current sourcing/sinking during the Miller plateau-where gate charge dynamics dominate switching loss. Its input stage provides logic-compatible thresholds (V_{IN_H} = 1.6–2.5 V, V_{IN_L} = 0.8–1.5 V) with hysteresis and reverse-current tolerance up to 500 mA.

Enable functionality is implemented on pin 3 with active-high logic, internal 100-kΩ pull-up to VDD, and defined threshold hysteresis (VEN_H = 1.7–2.7 V, VEN_L = 1.1–2.0 V). When disabled, OUT is forced low regardless of IN state-ensuring safe gate discharge in fault conditions.

Key Specifications

Pinout & Package

UCC27321DGN uses an 8-pin MSOP-PowerPAD™ (DGN) package with exposed thermal pad (3.00 mm × 3.00 mm body size). The PowerPAD enhances thermal performance by reducing θ_jc to 4.7°C/W and supports high-reliability operation from –40°C to +105°C ambient.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-side MOSFET driver applications.

Compared with UCC27322DGN, UCC27321DGN avoids logic inversion overhead in non-inverting control architectures; compared with TPS2829DBVR, it delivers 4.5× higher peak current and supports wider supply range-making it essential for high-power, high-voltage, or thermally demanding applications.

Availability

UCC27321DGN is available at Aetrix Electronics and suitable for switch-mode power supplies, motor controllers, and Class-D switching amplifiers requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for UCC27321DGN includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor company specializing in analog, embedded processing, and power management ICs, with leadership in high-performance power solutions and industrial-grade reliability.

The UCC2732x product line was designed specifically for high-current, high-speed low-side gate driving in demanding power conversion systems-including telecom rectifiers, server VRMs, and industrial motor drives-where Miller plateau current delivery and thermal robustness are critical.

FAQ

What is the logic configuration of UCC27321DGN?

The UCC27321DGN is a non-inverting low-side MOSFET driver: when the IN pin is high, the OUT pin goes high; when IN is low, OUT goes low. This matches standard PWM controller outputs driving N-channel MOSFETs referenced to ground. Its counterpart, UCC27322DGN, provides inverting logic. Both share identical electrical specs, pinout, and thermal performance.

Does UCC27321DGN require external pull-up resistors on the ENBL pin?

No, UCC27321DGN includes an internal 100-kΩ pull-up resistor from ENBL to VDD, enabling active-high operation by default. The ENBL pin can be left unconnected for standard enabled operation. An external RC network may be added only if controlled power-up sequencing or delayed enable is required-no pull-up is needed for basic functionality.

Can UCC27321DGN drive a 100-nC MOSFET effectively at 300 kHz?

Yes, UCC27321DGN delivers ±9-A peak current during the Miller plateau, enabling full gate charge (Q_g) delivery in under 11 ns (100 nC ÷ 9 A). At 300 kHz, total switching time remains well below 1% of the period (3.3 µs), preserving efficiency. Thermal data confirms 3 W dissipation capability in the DGN package-sufficient for this duty cycle with proper PCB copper area.

How does the UCC27321DGN handle ground separation between AGND and PGND?

UCC27321DGN mandates separate AGND (pin 4) and PGND (pin 5) connections tied together by a single thick copper trace directly beneath the device. AGND references input/enable circuitry; PGND returns high-current output paths. This separation prevents di/dt-induced noise on input thresholds-critical for stable operation in high-dV/dt environments like LLC resonant converters.

Is UCC27321DGN compatible with 3.3-V logic input signals?

Yes, UCC27321DGN features TTL/CMOS-compatible inputs with V_{IN_H} = 1.6–2.5 V and V_{IN_L} = 0.8–1.5 V across the full 4.5–15 V VDD range. A 3.3-V logic high exceeds the minimum 1.6-V threshold with margin, and hysteresis (0.25–0.90 V) ensures noise immunity. No level-shifting is required when interfacing with 3.3-V microcontrollers or FPGAs.